A novel arachidonic acid-selective cytosolic PLA2 contains a Ca2+-dependent translocation domain with homology to PKC and GAP
JD Clark, LL Lin, RW Kriz, CS Ramesha, LA Sultzman… - Cell, 1991 - cell.com
JD Clark, LL Lin, RW Kriz, CS Ramesha, LA Sultzman, AY Lin, N Milona, JL Knopf
Cell, 1991•cell.comWe report the cloning and expression of a cDNA encoding a high molecular weight (85.2 kd)
cytosolic phospholipase Az (cPLA2) that has no detectable sequence homology with the
secreted forms of PLA*. We show that cPLAz selectively cleaves arachidonic acid from
natural membrane vesicles and demonstrate that cPLA* translocates to membrane vesicles
in response to physiologically relevant changes in free calcium. Moreover, we demonstrate
that an amino-terminal 140 amino acid fragment of cPLA2 translocates to natural membrane …
cytosolic phospholipase Az (cPLA2) that has no detectable sequence homology with the
secreted forms of PLA*. We show that cPLAz selectively cleaves arachidonic acid from
natural membrane vesicles and demonstrate that cPLA* translocates to membrane vesicles
in response to physiologically relevant changes in free calcium. Moreover, we demonstrate
that an amino-terminal 140 amino acid fragment of cPLA2 translocates to natural membrane …
Summary
We report the cloning and expression of a cDNA encoding a high molecular weight (85.2 kd) cytosolic phospholipase Az (cPLA2) that has no detectable sequence homology with the secreted forms of PLA*. We show that cPLAz selectively cleaves arachidonic acid from natural membrane vesicles and demonstrate that cPLA* translocates to membrane vesicles in response to physiologically relevant changes in free calcium. Moreover, we demonstrate that an amino-terminal 140 amino acid fragment of cPLA2 translocates to natural membrane vesicles in a Ca*+-dependent fashion. Interestingly, we note that this 140 amino acid domain of cPLAz contains a 45 amino acid region with homology to PKC,~ 65, GAP, and PLC. We suggest that this homology delineates a Ca2+-dependent phospholipidbinding motif, providing a mechanism for the second messenger Ca2+ to translocate and activate cytosolic proteins.
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